


changing my face, bearing that pain

by birdginia



Category: Fate/Zero
Genre: Bad end, Choking, Double Penetration, Hate Sex, Large Insertion, M/M, Mild Gore, Other, Somnophilia, Tentacle Sex, improper use of time magic, it's fine it's Justice
Language: English
Status: Completed
Published: 2019-09-07
Updated: 2019-09-07
Packaged: 2020-10-12 02:17:13
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 1
Words: 2,555
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/20556575
Author URL: https://archiveofourown.org/users/birdginia/pseuds/birdginia
Summary: This is a miracle,the Grail tells him.And though he screams, and sobs, and claws at his skin and tears at his hair in anguish over the decision he must make—Who is he to reject such a gift?





	changing my face, bearing that pain

**Author's Note:**

> this was a request by an anon who wanted bad end kiritsugu to choke the shit out of kirei. i might have gone.....a bit overboard.

The Grail, in Irisviel’s shape, shows him the world he could have.

The suffering he’s always known, repeating without end.

The perfect world he’s been striving for, taken to its only logical conclusion.

“I wanted another way,” he cries, “I wanted a miracle!”

**This is a miracle,** the Grail tells him.

And though he screams, and sobs, and claws at his skin and tears at his hair in anguish over the decision he must make—

Who is he to reject such a gift?

-

It’s quiet.

Kiritsugu opens his eyes. The hall they’d just been using as a battlefield is pristine; no marks from either his fight with Kotomine nor from his sliver of a memory of the ceiling bursting open. An empty, white room.

Almost empty. 

Kotomine’s dark clothes are the only blemish on the smooth white of the room, drawing the eye instantly as Kiritsugu starts to stand up.

By the time Kotomine blinks awake, Kiritsugu is across the room, standing over Kotomine’s prone form as he considers his options.

They could continue their fight—over what, now? The Grail is—

**He is wicked.**

Kotomine begins pulling himself upright.

**He is evil to be purged.**

Kiritsugu’s gun is already loaded.

**He will be the first to fall before your new power.**

Kotomine smiles.

Kiritsugu strikes.

His hand is around Kotomine’s throat, his other with its finger on the trigger as he shoves Kotomine back to the ground and jams the gun to his temple. Kotomine grunts as the back of his head strikes the floor, and Kiritsugu feels the touch of a blade at his side.

And then, suddenly, he doesn’t.

There’s a wet hiss, and when Kiritsugu looks down, he sees molten metal, the Key in Kotomine’s hand falling away from Kiritsugu’s clothes. Kotomine’s eyes widen.

Kiritsugu turns his attention back to Kotomine’s throat, squeezing hard, and he should be surprised by the dark lines that start to creep up his wrist and spiderweb across his hand—but instead, it feels perfectly natural, as natural as breathing. As killing. He feels cold, the kind of cold that burns hot to the touch, everywhere he sees the marks on his hands, and he feels the chill crawl up the side of his neck, towards his face.

He must look like a monster, by now.

Kotomine is still smiling.

Kiritsugu tosses his gun aside, freeing his hand to increase the pressure on Kotomine’s throat, sinking all of his weight into the effort of crushing Kotomine’s windpipe. He’s not used to this, such a close-range kill, but it feels right, somehow. Putting all of himself into the punishment of evil.

Kotomine takes a hand, unarmed, and wraps it around Kiritsugu’s wrist. His grip is weak, the light in his eyes is fading, but he isn’t making any effort at all to pry Kiritsugu’s hands away.

Kotomine mouths something, the sound only a soft creak of breath.

_We’ve found it._

Kiritsugu does not let go.

_Our purpose._

Kiritsugu shifts his weight.

_Our passion._

Kiritsugu takes his hands away, and Kotomine’s hacking gasps for air fill the otherwise silent room. 

“I have known my purpose,” Kiritsugu says. “To destroy what is wrong with this world, and save those who are right.”

“Your—“ Kotomine coughs, and coughs, until it morphs into a fit of laughter, his body shaking with it. “Your purpose—is to bring death. You will create any excuse to snuff out a life.” He puts a hand to Kiritsugu’s cheek, tracing the ice-cold line down his neck with a finger. “It is the only way you can find—joy.”

Kiritsugu slams Kotomine’s hand to the ground, rage pulsing through his blood—or what now flows through him after his covenant with the Grail. Kotomine continues to laugh, and Kiritsugu adjusts his body so his next assault on Kotomine’s throat will be final.

But in the process, his hips shift over Kotomine’s, and Kotomine is—

**He is not only evil.**

**He is a perverse abomination.**

Kiritsugu feels bile rise in the back of his throat.

**Death is too good for him.**

There’s a sharp pain in Kiritsugu’s back, and a sickening tearing sound that could be fabric or flesh, and then both of Kotomine’s wrists are pinned to the ground, stretched to his sides in a parody of crucifixion. Any surprise Kiritsugu might have felt fades quickly as the voice of the Grail continues to whisper to him, telling him what is to be done with Kotomine as ribbons of darkness start to carry it out. 

Kotomine opens his mouth, but a thick tendril shoves itself inside, silencing whatever filthy comment he had planned. There’s a wet gurgle and then a choked noise of shock as a bulge starts to form in Kotomine’s throat. Maybe now he will stay quiet. 

Still more tendrils burst from underneath Kiritsugu’s skin and twine around Kotomine’s legs, holding them in place to avoid any kicks or attempts to break out of Kiritsugu’s hold. He feels the faint sensation of pressure somewhere outside his body, and when he looks up, Kotomine is struggling with the foreign body invading his mouth, futilely trying to bite down on something holding his jaw too wide open for him to have much purchase. His eyes are starting to grow hazy and unfocused, lack of air starting to weaken him.

With a thought, the thing starts to slip out of Kotomine’s throat, giving him just enough room to breathe through his nose in wheezing gasps.

**He must be ruined.**

**Violated.**

**Mastered.**

Kiritsugu feels like he’s drowning, like any rational thought of simply putting a bullet in Kotomine’s skull and ending this now is being replaced by a viscous sludge whispering promises of justice, of power, of utter debasement of anything in his path. 

Something bursts out of Kiritsugu’s chest—another thick vine of darkness, this one dripping with what looks like black blood and viscera. It lands on Kotomine’s stomach with a sickening sound, the black ooze blending in with his dark clothes to leave a slimy sheen as it moves over his chest. It writhes aimlessly for a moment before curling around Kotomine’s waist and pulling, the tension tugging at Kiritsugu’s chest and tightening his breath until he moves Kotomine’s body the rest of the way, flipping him onto his stomach. 

The tendril in Kotomine’s mouth starts to choke him again, and then ones around his limbs curl tighter, while the one from Kiritsugu’s chest starts to shove its tapered tip underneath Kotomine’s waistband.

**”Is this the pleasure you seek?”** Kiritsugu hears distantly in his own voice as he feels the tendril slide down, down, meeting resistance for only a moment before tearing Kotomine open.

Kiritsugu nearly vomits at the ghosts of sensation he can feel from the bizarre tentacles springing forth from his body—the multiple rings of muscle enveloping limbs he’d never had before. It feels wrong, to be this intimately close to Kotomine, but it’s overpowered by the feeling of justice, of retribution, of power over something he previously could not control.

The tendril inside Kotomine goes deeper, sliding almost easily with both its own fluids and Kotomine’s rapidly drawn blood. The thickening length meets with resistance, but the unnatural creation ignores it and powers onwards, stretching him wider and wider. Kiritsugu can almost feel the ground underneath Kotomine’s stomach as it keeps pressing in deeper. 

And then, it stops.

It doesn’t move to fuck him as a lover would—instead, it stays still, keeping him spread wide open on both ends and barely conscious enough to struggle. The silence of the room stretches on for as long as the Grail wishes it to.

What breaks the silence is Kotomine. He can still barely breathe, but somehow there’s still enough space in his throat to allow him a long, low noise. It could be a moan of discomfort, pain, fear, but by now Kiritsugu knows otherwise.

**”Abomination.”**

A few short puffs of air—laughter—and Kotomine starts to move, shifting his hips as if inviting further intrusion, and his hands clench and unclench involuntarily.

Kiritsugu feels rage bubble over in his broken-open stomach, and the tentacle starts to move again. It slowly retreats just a few inches, then slams back inside, an impact more than a thrust, crushing Kotomine’s insides against themselves and forcing grunts of effort out of Kotomine’s throat. 

And then it does it again, and again, out of time with the rhythm of the other tentacle keeping Kotomine just on the edge of asphyxiation. Everything feels tight, inside and out, and the movement is almost satisfying as Kiritsugu lets his body—**their** body—do what it pleases.

The satisfaction only grows as the tendrils wrapped around Kotomine’s arms start to form bruises, the one in his ass tastes more blood, and the one in his mouth becomes soaked with acid and saliva. It’s better than spilling his brains against a wall, or his organs on the floor; it’s personal, visceral in the most literal sense. It’s dizzying.

Kiritsugu has never associated his work with pleasure—though, admittedly, he could count the things he does associate with pleasure on one hand. But this power, this pure destruction of something evil, all of it makes his disgust and his rage slowly dissipate as his body lights up with long-overdue relief.

He finds himself buzzing with every muffled groan from Kotomine’s throat, the sounds now more pain than anything, his blood going hot with every tear that falls from Kotomine’s eyes. He finds the squeeze of Kotomine’s muscles around his pseudo-limbs to feel close to a woman’s touch—though he pushes any memories of the past out of his mind as quickly as possible. Neither of them deserve to be associated with such an act of violence.

He finds a moan start to bubble up at the back of his throat, a noise of exhaustion and agony and total satisfaction as he wills the tendrils to go faster, break Kotomine apart more and more, hold his arms tight and his legs further apart to accommodate for the widening girth inside him. He feels his own cock fill with whatever his body now contains instead of blood, but he ignores it for now, occupying his hands with Kotomine’s hair instead, pulling it hard and bending his head back so he can get a better look at Kotomine’s face. 

There’s still something in his eyes that isn’t scared, or hurt, or repentant, and Kiritsugu pulls harder until Kotomine’s eyes flutter closed. 

It’s good enough. He slams Kotomine’s forehead to the ground.

The coils binding Kotomine’s wrists have been constricting progressively harder around him, and Kiritsugu can see his hands start to change color, from red to a dull purple. He thinks about continuing the pressure until they become completely useless, maybe tear them off entirely, maybe continue tearing pieces of him off, layer by layer, skin to muscle to bone, up his arms and legs and eventually tearing him fully apart, to leave him staring at the remains of his insides, compressed by the monstrosity ripped from Kiritsugu’s own body and then ripped open again to spill onto the pristine floor.

He’s never pictured a death so vividly before. 

He’s never pictured something that could so easily become reality.

His unnatural arousal does not wane, even with such gruesome imagery in his mind—though, perhaps, this is what he now craves, what the Grail has allowed him to take joy in. Maybe he was never meant for normal, loving sexual relations—he certainly pushed away his chances of those before he came here. Maybe it’s only right that before he can consciously will it, the writhing thing inside Kotomine slips out, twining its way around one of Kotomine’s thighs to stretch him open, almost invitingly. 

Kiritsugu takes a breath.

And lets go.

The entry is smooth, easy, with whatever his new appendage was secreting slicking the way and how distended Kotomine’s entire body is by now. Kiritsugu’s cock is nowhere near as large as the largest point of the tentacle’s body, but it’s still a warm, tight hole that his only-human cock has been seeking out. He thrusts in once, then twice, then Kotomine starts to tremble, his hips grinding into the ground for a few moments and his body clenches around Kiritsugu’s in sharp pulses before he lets out a long, slow breath. 

Kiritsugu wills the tendril in Kotomine’s mouth to retreat, and Kotomine _laughs_, a rough, ruined noise that’s interrupted by a coughing fit but sounds no less triumphant.

“I knew we were the same,” he says.

Kirtsugu grabs for Kotomine’s hair again, and breaks his nose against the floor.

The tightness around Kiritsugu’s cock only intensifies, and Kotomine’s gasps of pain do not sound as such. He almost commands the tendrils to stuff his throat again, but instead, he covers Kotomine’s mouth and nose with his hands, feeling Kotomine’s struggle directly rather than through the foreign limbs. 

Kotomine can no longer laugh as his eyes go dim, his chest spasms, and he eventually goes limp, leaving Kiritsugu with a broken doll to fuck.

The self-hatred that had been pushed down by the force of the Grail’s intrusion into his body and soul starts to rise again like bile in his throat, but then retreats. He’s free to do with Kotomine as he wishes, now, completely ruin him inside and out without seeing the smug look in his eyes, without hearing his taunts. 

He should kill Kotomine now. Surely he’s done enough to desecrate this monster beneath him.

Instead, he keeps thrusting, fucking Kotomine’s near-corpse until he comes with a cry. He feels hollow, all his insides scraped out to leave a husk of dead skin behind. As if this was all he had in him.

He isn’t satisfied.

_”Time Alter: Double Accel.”_

He’s not as young as he used to be, but his body speeds through its processes even quicker than it would before, his magic doubled and doubled again by the miraculous power within him.

He fucks Kotomine again.

It takes longer, this time, agonizingly so. He bites down on the back of Kotomine’s neck, tasting his blood, desperately trying to take back whatever he’d lost, whatever he’s still losing, inside of Kotomine.

The buildup takes so long, he almost considers increasing his speed again, and Kotomine starts to stir under him with a groan. 

Kiritsugu pulls his face into view, and Kotomine looks dazed and exhausted, any joy he’d been deriving from Kiritsugu’s treatment drained.

The tendrils around Kotomine’s wrists pull at him harder, wrenching his shoulders upwards until Kotomine’s face contorts in pain. Kiritsugu lets the high of finally feeling like he’s won carry him as he tightens his grip on Kotomine and fucks him hard. His body moves so much more easily when he stops thinking and lets instinct take over. He’s always had sharp instincts, after all. 

Kiritsugu closes his eyes as he feels heat wash over him, spreading through his body and fighting back the ice cold of the Grail until he finally comes again, collapsing against Kotomine’s back as he shudders through it. 

Kotomine opens his mouth to say something, and another tendril shoots out of Kiritsugu’s stomach to cover his mouth.

It’s right.

**It’s right.**

Kotomine might need to be punished a little longer.

**Author's Note:**

> my twitter is over at [@Slotheyyyyy](https://twitter.com/Slotheyyyyy), check it out if you want to make a request or just absorb my forbidden horny knowledge!


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